Enclosure for shooter

ABSTRACT

The enclosure surrounds the shooter who fires his/her weapon from inside, adjacent the back wall, at a target and/or bullet trap located some distance away from the enclosure. Sole access to the enclosure, and the shooter&#39;s station therein, is through the open front end. Air circulation and filtration is supplemented by generating an air curtain across the open front end. Air venting and filtration of inside air is at a rate of 6 times per minute and provides a flow of clean air from back to front of the enclosure through a pressurized plenum in the back wall designed to create a uniform flow through the shooter&#39;s station. An auxiliary venting outlet in the top or ceiling of the enclosure provides a negative air pressure inside the enclosure so contaminated air escaping through the open front end is minimized.

BACKGROUND OF INVENTION

This application incorporates by reference U.S. Patent ProvisionalApplication Ser. No. 61/827,136 filed May 24, 2013 and claims prioritythereto in so far as common subject matter/invention is included.

Shooting ranges generally require considerable real estate toaccommodate a shooter sitting or standing and firing his weapon at atarget located 25 or more feet from the shooter. Shooting clubs andfiring ranges are sometimes fully enclosed, and equipped with airexchanging capability, plus, they must provide access to the targetarea, all factors that further increase the need for considerable realestate, whether located inside a building or outside.

There is a need, therefore, for a shooter's enclosure that can be usedwith a compact bullet trap, in a residential basement, or other confinedspace, and yet provide for both noise reductions and accommodate thewaste products of firing weapons, and satisfy the environmental concernsof even the most fastidious homeowner. Such concerns are met with anenclosure having the features to be described.

The present invention provides an enclosure that satisfies theseconcerns, and that can be used with a bullet trap of suitable design.The inventor refers to his co-pending application Ser. No. 13/475,511filed May 18, 2012 for a description of such a bullet trap. Thatco-pending application is incorporated by reference herein.

SUMMARY OF THE INVENTION

In accordance with the present invention a generally rectangular walledstructure is provided with a single access opening at the front endthereof. This open front end is aligned with and faces the bullet trap,and inside of the enclosure, adjacent the back wall, a shooter's stationis provided at some predetermined distance from the target area of thebullet trap.

The inside of the enclosure is maintained at a slight negative airpressure relative to the ambient air external to the enclosure. Air inthe enclosure is circulated through a closed system where it isfiltered, and some air from inside the enclosure is vented outside ofthe enclosure, and/or outside of the building in which the enclosure islocated.

The air circulation and filtration system supplies filtered air to apressurized plenum built into the back wall, and delivers a uniform airflow from back to front of the rectangular enclosure. An air curtain iscreated across the enclosure adjacent to the front end, by means of ablower inside a housing designed for this purpose, and located on oneside wall of the enclosure. On the opposite wall of the enclosure, airis drawn into a housing where it is filtered and re-circulated, forreturn to and pressurizing of said plenum located in the back wall ofthe enclosure.

Among the many unique features of the shooter's enclosure, the followingare particularly significant: first, baffles are provided on the sidewalls, to better absorb the noise generated by the firearm, and byreason of the location selected for said baffles the air flow inside theenclosure is more closely controlled, assuring that any flow through theopen front end is minimized. Second, air dams are provided justdownstream of the shooter's station to increase airflow velocity in thisarea. This assures that gasses created during firing of the weapon arenot allowed to collect in the area of the shooter's station where theshooter might otherwise suffer the ill effects of the noxious fumesgenerated by successive firings inside the enclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows, schematically and in perspective, an enclosure with anopen front end, and air re-circulating and venting apparatus in selectedlocations for maximizing the advantages of my invention.

FIG. 2 shows, in horizontal section, the enclosure of FIG. 1,illustrating the interior features thereof.

FIG. 3 is a perspective view looking into the front end of the enclosureto the shooter's station.

FIG. 4 is an exploded view of the components comprising the plenumchamber in the rear wall of the enclosure.

FIG. 5 shows the components depicted in FIG. 6 as assembled.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to FIG. 1 in greater detail, the rectangular enclosure ispreferably made largely from conventional components, many of which areavailable from suppliers such as STANCO, a supplier of sectionalenclosures, SOUNDSEAL, a supplier of sound deadening blankets, andMARSAIR, a supplier of air curtain generating equipment.

In it's presently preferred form the enclosure is rectangular inplan-form, with side walls 10 and 12, supporting a top wall 14. The backwall 16 defines a plenum chamber in which mutually perpendicular grids,18 and 20, provide a grid structure into which air is forced into therear grid 18, as suggested by the arrows 22, 22, and then into the frontgrid 20, and through a grille 26, from pressurized air in a plenumchamber 24 located at the back of the enclosure and described in detailwith reference to FIG. 4.

The grid structure of FIG. 4, serves to turn the air flow from theinitial direction 22, to a downstream direction as indicated by thearrows 28,28 in FIG. 2. Horizontal dividers of rear grid 18 and frontgrid 20, have a foraminous sheet 25 sandwiched between these grids tocreate a generally uniform flow of air from the back toward the frontinside the enclosure. The grille 26 and grid structure of FIG. 4 occupythe entire back wall of the enclosure for this purpose. See the arrows28,28 for a schematic attempt to illustrate this airflow pattern.

The grid structure of FIG. 4 defines the plenum chamber 24 in the rearwall 16 of the enclosure behind the shooter's station. Two foraminoussheets 25 and 27, best shown in FIG. 5, cooperate with the gridstructures, 18 and 20, to divert the air flow from the incomingdirection of arrows 22, 22 through the grille 26 to the downstreamdirection as suggested by arrows 28,28. The rear most wall 33 of theenclosure is solid and in cooperation with the sides and top walls ofthe enclosure defines the plenum chamber 24.

FIG. 2 shows a shooter's station, with a table 30 behind which theshooter positions himself for firing out through the open end 32 of theenclosure at a target, and/or bullet trap located a predetermineddistance from the shooter's station outside the enclosure. Preferably,suitable warning systems are placed in the general area of the enclosureand the target/bullet trap so as to avoid injury to persons or propertyin this general area. Motion detectors are recommended for placement atstrategic locations in this area, and warning devices inside theenclosure (aural and visual) alert the shooter to such intrusions andthe need for cease firing from inside the enclosure. Thus the front endof the enclosure defines a relatively large opening 32 for accommodatingthe shooter's visual field of the target/bullet trap.

In further accordance with the present invention, and to prevent noxiousfumes and other products of combustion from the fired weapon escapingfrom the enclosure, the interior of the enclosure is maintained at aslight negative pressure relative to ambient pressure outside theenclosure. Additionally, and to protect the shooter from these noxiousgasses of combustion and particulates hostile to his environment,several design features serve to minimize these environmental hazards asfollows; The downstream air flow pattern inside the enclosure carriesthese gasses and hazardous particles away from the shooter's station,where these gasses and entrained particles can be collected by aircirculation and filtration units to be described.

The majority of ventilation air will be drawn into a collection chamber34 for return to the plenum chamber 24 associated with the back end wall16 of the enclosure. To create the desired negative ambient air pressureinside the enclosure, an air-venting unit 36 is provided in the top wallof the enclosure adjacent to the open front end, and a vent pipe allowsair from unit 36 to escape from the enclosure as suggested by the arrows38, 38 to the outside world, that is, outside of any building in whichthe enclosure is placed for example. Thus a slight negative pressure ismaintained inside the enclosure.

The air re-circulating unit, or units, associated with the chamber 34have multiple filters that can be replaced periodically in accordancewith regularly scheduled maintenance protocols. So too, the vent unit 36is fitted with air filtering capability as well. All such filters areaccessible from inside the enclosure, and may be monitoredelectronically for automatic signaling to the shooter who will berequired to activate a control system before assuming an active positionat the shooter's station.

The rear wall 16 of the enclosure includes a pressurized plenum chamberthat directs ventilating/filtered air forwardly toward the front/openend 32 of the enclosure. Thus, air contaminated by the shooter's weaponfired at the shooter's station 30 is directed forwardly as suggested bythe arrows 28, 28 in FIG. 2. This contaminated air is drawn throughfilters in the cabinet 34. A four-stage filtration system is provided,comprising: a pre-filter, ring filter, charcoal filter, and a HEPAfilter, all arranged in series. Air is re-circulated at a rate of atleast 6 times per minute. This rate of air flow coupled with the slightnegative pressure created by exhausting some contaminated air toatmosphere through the ceiling vent 36, assures that the shooter doesnot suffer any ill effect from the enclosed space at the shooter'sstation.

In addition to placement of the inlet, or inlets, to the collectionchamber 34 close to the front end of the enclosure, another importantfeature of the present invention is placement of a self contained aircurtain generating device 40 on the wall 12 opposite the vent unitinlet, or inlets, in the wall 10 associated with the air recirculationductwork. FIG. 2 shows this air curtain generating unit 40 in a cornerdefined by one of several strategically placed baffles, 42, 42 providedon the inside of side walls 10 and 12. Whereas conventional air movingblowers and air filtering apparatus are contained inside therecirculation and filtering system, the self contained air curtaingenerating device 40 simply draws in ambient air from inside theenclosure and directs an air curtain of high velocity air from one sidewall 12 toward the opposite side wall 10, and more particularly in adirection such that this air reaches the vent inlet where the filtersare located, cabinet 34.

The above-described configuration assures that no appreciable quantityof contaminated air escapes from the enclosure, and that the majority ofthis air is either re-circulated through the filters provided at 34, orexhausted to the outside world through the unit 36. Filters are providedin unit 36 as well, and monitored in the same way as those provided forthe re-circulated air by a control system to be described.

The baffles 42,42 include portions that hang downwardly from the insideof top wall 14, and such baffles serve to slow the flow of airdownstream along these walls and along the inside of top wall 14. Thisslowing of such air-flow, in the relevant regions inside the enclosure,increases slightly the air pressure in these regions, that isimmediately upstream of these baffles. Consequently, by placing the airinlet vents behind these baffles 42, 42 greater efficiencies in the airflow into the blowers can be achieved.

A further function for these baffles 42, 42 is simply to reduce thenoise generated by the shooter when firing his weapon at the shooter'stable/station 30. The side walls and roof are of laminated pressboardwith sound insulating core, and are vinyl coated. Quilted fiberglasssound absorbing blankets, about 2″ thick, are hung on the inside of theside walls and also mounted to the ceiling of the enclosure. Muzzleblast noise is reduced by 75%, to a level less than that inside anairport terminal for example.

While the baffles 42, 42 are so placed as to slow the flow of air inthese regions, air dams 44, 44 are placed immediately downstream of theshooter's station to accelerate air flowing over these dams, andheighten the rate at which contaminates are drawn downstream, beyondthat achieved by the air flow pattern from the grille and grid structuredescribed previously. These dams 44 create a cross sectional areareduction in the enclosure causing an increase in air velocity justdownstream of the shooter's station, assuring him, or her, of adequatelyfiltered air when rapid firing of his weapon might otherwise be expectedto create greater exposure to noxious gasses and other products ofcombustion at the shooter's station. Preferably, the right side wall 12dam 44 is located rearwardly relative the dam on the left side wall 10.

The enclosure described herein is designed for use in a residence, orother building that has occupants who should be protected from harmduring the firing of a weapon, from inside the enclosure, to a targetlocated outside the enclosure. Therefore, a perimeter alarm systemshould be installed in the building where the enclosure is located. Suchan alarm system has motion detectors or other sensing devicesstrategically mounted at access points to the space utilized for theenclosure and associated target area. These detector devices must beactivated before firing a weapon, and indicators inside the enclosureare provided to alert the shooter when these devices are inactive. Oncethe system is activated, the shooter will be alerted to a trippeddetector device by automatic activation of a light or other warningdevice inside the enclosure. Preferably a flashing red or yellow lightis energized in response to a detector device being tripped. Anotherwarning device such as a klaxon horn may also be activated to warn boththe intruder and the shooter when electrical power has been turned oninside the enclosure and someone has tripped one of the detectiondevices in the area.

A further feature of the shooter's enclosure is provision, inside theenclosure, for warning the shooter when the air filters requiremaintenance or replacement. When the design air flow rate (75-100 feetper minute) drops below this range, a warning device alerts the shooterto the need for checking these filters and replacing and/or cleaningthem in accordance with recommended periodic maintenance requirements.It is also recommended that a rug be placed on the floor inside theenclosure to serve two purposes, first to aid in noise reduction duringfiring inside the enclosure, and second, to entrain particles that arenot carried away by the ventilation and filtration system. It is alsorecommended that this rug be cleaned periodically, preferably by anindustrial style high efficiency HEPA vacuum capable of capturingparticles of 0.03 microns with 99.97% efficiency.

1. An enclosure for use by a shooter at a shooter's station definedtherein, the shooter able to fire from said station at a target locatedoutside the enclosure, said enclosure comprising; a generallyrectangular walled structure having one and another side walls and a topwall, and including front and back ends, the front end beingsubstantially open, said back end defining a pressurized air plenumcreating a generally uniform air flow from back to front of saidenclosure, an air circulating and filtration system supplyingpressurized air to said plenum, and including at least oneair-ventilating unit accessible from inside said enclosure, and an aircurtain creating unit provided oppositely to at least one said airventilating unit inside said front end of said enclosure to provide acurtain of air between said enclosure side walls adjacent to said openfront end thereof.
 2. The enclosure of claim 1 wherein said pressurizedair plenum comprises a grid for receiving air from said air ventilatingunit discharging that air so received in a generally uniform flowpattern from said back end toward said open front end, and between saidside walls of said enclosure. Said grid including at least oneforaminous sheet therein.
 3. The enclosure of claim 2 further includingair flow diverting dams provided on said side walls inside saidenclosure to accelerate the airflow downstream of said shooter'sstation.
 4. The enclosure of claim 3 further including an auxiliary airventilating unit in said top wall adjacent said open front end of saidenclosure for reducing the ambient air pressure inside said enclosure byexhausting air to a location remote from said enclosure, said auxiliaryunit operating independently of said air circulating and filtrationsystem.
 5. The enclosure of claim 1 wherein said air curtain unit has aninlet side drawing air from inside said enclosure adjacent one of saidside walls, opposite said air ventilating unit, and said air curtainunit directing the air curtain laterally and generally normal to saidone side wall, said air ventilating unit drawing air from inside saidenclosure adjacent the other of said enclosure side walls and generallyoppositely from said air curtain discharge direction.